https://stackoverflow.com/questions/32414942/python-scroll-speed
At least on Win7, tk.Texts scroll, by default, at an anemic 2-3 lines per wheel click, ignoring the system wheel setting. What happens on other systems? I consider this a probable tk bug, at least on Widows, but we can override the default (on Windows) with

def mousescroll(event):
   <scroll n lines>
   return 'break'
text.bind('<MouseWheel>', mousescroll)

turtledemo.__main__ has wheel code (for font resizing) for Windows, Linux, and Mac. Unless we can access system settings, we might add a config option.

On X Window the scroll step in text widget is constant (50 pixels). On Windows and Mac OS it should depend on mouse settings.

Run with, execute

bind . <MouseWheel> {puts %D}

and try to roll mouse wheel on Tk window with different speed and settings.

The SO OP reported Idle Shell and Editor behavior. I retested minimal tk.Text(root).pack(), eliminating Idle as a factor, before and after changing system lines setting from 3 to 9, and got the constant same behavior. The now too small 50 pixels seems about what it is doing.

Serhiy, I do not understand your 'Run ...' sentence.

You can measure your mouse speed with following pure Tcl/Tk script.

Or with following Python script.

Serhiy, I do not understand your 'Run ...' sentence.

Sorry, there was a typo in my sentence. I meant "Run the program 'wish' and enter the following command".

This is 'out of date' in the sense that I have decided that the root problem is scrolling by pixels instead of lines. Once we do the latter, for bpo-33664, we can just scroll by, say, 5 lines instead of 3, which I think is sufficient.